Outdoor man-made waterfalls, with a minimum vertical fall of 5 feet and a continuous flow of water for most of the year. This includes waterfalls created by dams, aqueducts, weirs, hydro-electric power stations, garden waterfalls, sculptures, etc.

The largest producer of hydroelectric power in the country, Grand Coulee Dam was the largest concrete structure in the world when built, containing 11,975,521 cubic yards of concrete. It remains the largest concrete structure in the country.